The blazer is one of a guy's most important wardrobe staples. It's endlessly versatile, working in a variety of situations and with a huge array of outfits. Though lapel widths and number of buttons change,it's a steadfast ally on the front lines of men's fashion. Not all blazers, however, are created equal. For all the great ones out there, there are plenty of unfortunate, unstylish specimens. Learn how to spot high quality and classic style, and pay attention to proper fit, and you'll find blazers that'll become old friends.

Fit Is Key

Never forget the most basic tenet of the suit jacket: Fit is key, and when that is lost, you're on a slippery slope to looking uncomfortable, slovenly or downright juvenile. If the fit is off, it doesn't matter what the fabric or pattern is or what else you may be wearing, as you're likely to resemble either something in a deli window or Tom Hanks' character at the end of the movie "Big."

Remember why you chose to don a blazer, and go from there. "The goal of wearing a suit is to look powerful and masculine, with broad shoulders and a slim waist," says George Kotsiopoulos, fashion expert and co-host of "Fashion Police" on E! Entertainment Television. "A boxy suit either makes you look bigger than you are, or---if you're small---it makes you look even smaller. If your jacket length extends to your fingers and your sleeves are too long, you'll look like you're playing dress-up in your dad's closet---and there is nothing manly about that."

Birth of the Blazer

Nowadays, a blazer is almost any jacket that is cut in the style of a suit coat, but with a nod to the more casual. The blazer is commonly believed to have been born in 1837, when the commander of the frigate H.M.S. Blazer learnt of an impending inspection of his ship by the then-young Queen Victoria. Looking out on the sorry state of his crew's dress, he ordered that his crew get new uniforms, and thus, the blazer was born.

Blazer Basic(s)

After you've got the right fit, next make sure to keep your look classic and timeless, no matter what the trends are attempting to dictate. It's easy enough to get caught up by what other people may be wearing, but a look back to the decade of blazer abuse that was the '80s can serve as a jarring reminder that simplicity is key.

Getting started with what can become your go-to suit jacket takes a little bit of confidence mixed with a generous portion of restraint. "Every man should own a single-breasted, one- or two-button, navy or grey blazer," Kotsiopoulos said, "Look for a slim-fitting, but not skinny, blazer with high-cut armholes. The most fashionable blazers are super-tailored around the torso, a bit shorter and very slim on the arm."

Others quickly echo this fashion sentiment. "For the all-purpose blazer, it's good to stick with clean, simple lines, and a solid fit," Brian Spaly, CEO of Chicago-based Trunk Club, said. "Charcoal or black, lightweight wool, with a simple notch lapel is best. You're doing yourself a favour when you avoid frilly details like brass buttons, peak lapels, and other fancy odds and ends. And don't ever wear a blazer with embroidery or bedazzlement."

It's also important to be seasonally appropriate. "Worsted wool is the ideal fabric for a first blazer because it can pretty much be worn year-round," said Kotsiopoulos. But there are many other types of wools, he notes. "Tweed and flannel are the heaviest wools, and best for winter," he notes, "while tropical wool is lightweight and perfect for summer." Kotsiopoulos notes cotton and linen are good summer choices, too.

But it's not just what blazer you're wearing, but how you wear it that counts. "Never wear the same colour trousers and blazer unless you're wearing a suit!" says Spaly. "Always tuck your shirt in if you're wearing a blazer, unless you decide to wear it over a T-shirt. And in that case, V-necks are most preferable."

The Modern Blazer

There was a time when the notion of jeans and a blazer simply wasn't an option, but fortunately for a denim-dedicated society, pairing the two has gone from cowboy to commonplace.

"We are at a point now where jeans are acceptable to wear anywhere as long as your look is well-tailored," Kotsiopoulos said. "For a night out you can easily substitute a pair of dark, slim-fitting, straight-legged jeans with your suit look."

Even with the flexibility that a well-fitted blazer offers your wardrobe, some simple (and somewhat obvious) rules still apply. "Guys should never wear a blazer with ripped, faded or distressed denim," Spaly said. "It just looks silly, and the best jeans to wear with a blazer are of the clean-finish, dark-wash variety. Pair a blazer with dark jeans, a nice dress shirt, and some simple but elegant shoes." Remember, a great blazer can make a good outfit great, but it can't save a bad outfit.